He started his medical career at St Bartholomew's Hospital, London, and was appointed consultant physician in 1904; he held this post until 1919.

At the outbreak of the First World War, Herringham was a lieutenant-colonel in command of the medical unit of the London University OTC.

[1] Between 1914 and 1919, he was consultant physician to the British Forces in France in the Royal Army Medical Corps, initially as a Colonel and rising to the rank of Major-General in 1918.

[2] Herringham was already sufficiently well known that his army appointment was reported in the New York Times under the headline "Famous Doctors to Front".

In 1906, Herringham accompanied her to India where on this and another visit, she made copies of the Buddhist cave paintings at Ajanta near Hyderabad, which were deteriorating badly.

[11] By 1911, Herringham's wife suffered from delusions of pursuit and persecution and was admitted to an asylum, spending the rest of her life in mental institutions.